Conventionally, in such type of a microwave oven, a sheet-shaped console switch unit serving as an input unit is formed by coupling a decorative sheet on which a cooking menu is printed and upper and lower printed electrode sheets that form switches (see, Japanese Patent Laid-open Application No. H6-229567).
Further, since a plurality of cooking patterns is stored in a memory, if a user selects a desired cooking menu by manipulating a control panel such as the sheet-shaped manipulating switch unit or the like, a microcomputer is used to operate a heating unit, e.g., a magnetron or the like, in accordance with the cooking patterns stored in the memory (see, U.S. Pat. No. 6,744,026).
FIGS. 4 and 5 show a conventional microwave oven disclosed in Japanese Patent Laid-open Publication No. H6-229567. As illustrated in FIGS. 4 and 5, the conventional microwave oven includes console's main body 1; microcomputer 2; printed circuit board 6 having thereon selecting unit 4 composed of jumper wire 3 and memory 5 for storing a plurality of cooking patterns; decorative sheet 7, e.g., a PET film having cooking menus printed thereon; and upper and lower printed electrode sheets 9a and 9b respectively having printed electrodes 8a and 8b on locations corresponding to positions where cooking menus are printed. Upper and lower printed electrode sheets 9a and 9b are connected to printed circuit board 6 as well as to microcomputer 2. Microcomputer 2 continuously detects which printed electrode is closed. If a user pushes a key for a desired cooking menu on decorative sheet 7, e.g., a key for milk, printed electrode 8a of third and fifth pins P3 and P5 makes a contact with printed electrode 8b, so that the circuit is closed. At this time, microcomputer 2 determines that the cooking menu of milk is selected and, thus, executes a process to operate a heating unit (not shown), e.g., a magnetron or the like, in accordance with a heating pattern for milk, which is stored in memory 5.
Meanwhile, microcomputer 2 selects one set from a plurality of cooking menu sets by using selecting unit 4 composed of jumper wire 3 provided on printed circuit board 6. For instance, in an American microwave oven, an American menu such as “popcorn”, “bacon” and the like is selected from cooking menu sets of various countries by positioning jumper wire 3 at J1, whereas in a Japanese microwave oven, a Japanese cooking menu in which, “” and/or “” is warmed is selected by positioning jumper wire 3 at J2. In a decorative sheet for the American microwave oven, “popcorn” and “bacon” are printed, whereas one for the Japanese microwave oven, “” and “” are printed on decorative sheet 7.
In order to manufacture a microwave oven that can be used in several countries, it is configured such that exclusive decorative sheets are arranged to match with corresponding exclusive connection positions of jumper wire 3 for respective countries.
Since, however, decorative sheet 7 and upper printed electrode sheet 9a are separate components in the conventional configuration, a considerable force is needed to close the switch circuit by transforming the printed electrode sheet due to a thickness of decorative sheet 7 and that of upper printed electrode sheet 9a. Further, since they are of separate components, a menu print position printed on decorative sheet 7 can be misaligned with an electrode print position due to a deviation in an operation.
Moreover, if a position of jumper wire 3 attached to printed circuit board 6 is combined with wrong decorative sheet 7 when it being manufactured, in case a key for popcorn, for example, is pushed, a cooking of milk can be carried out. For this reason, a desired cooking performance cannot be achieved.
To solve such problem, an alternative route may be taken wherein the cooking menu sets are reduced by component standardization. However, in this case, an American cooking menu and a Japanese cooking menu have to be combined, for example, so that a microwave oven does not certainly meet the user's preference.